Render has more objects than camera view
Try pressing Alt + H in Object Mode to unhide all objects. It is possible that you accidentally hid some of them so you don't see them in Object Mode but you do in the render.

Also since you used a particle system check, if you used children then it's possible that the number of children to render is different from the number of children to display. To check this go into the Particle System tab under children.

If you are using cycle, select the object that isn't displaying and go in the Object tab, under Cycles settings make sure that Camera is checked.